[MM-61691] Deleting drafts when permanently deleting a user (#30233)

* deleting drafts on permanently deleting user

* verified count of drafts before deleting

* i18n fix

* use ExecBuilder

* changed error message to specify user

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Harshil Sharma <harshilsharma63@gmail.com>

server/channels/app/user.go

@@ -1832,6 +1832,10 @@ func (a *App) PermanentDeleteUser(rctx request.CTX, user *model.User) *model.App
 		return model.NewAppError("PermanentDeleteUser", "app.scheduled_post.permanent_delete_by_user.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
 	}
 
+	if err := a.Srv().Store().Draft().PermanentDeleteByUser(user.Id); err != nil {
+		return model.NewAppError("PermanentDeleteUser", "app.drafts.permanent_delete_by_user.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+	}
+
 	if err := a.Srv().Store().Bot().PermanentDelete(user.Id); err != nil {
 		var invErr *store.ErrInvalidInput
 		switch {